Robotic equipment is commonly employed in many industrial applications. In one important application, robotic equipment inserts electronic components into predetermined locations on printed circuit boards. Commonly, the boards are passed along an assembly line on a conveyor. At separate stations along the line, insertion machines insert components of the same type. The robotic equipment of the prior art are generally unable to handle more than one size or shape of components without changing or modifying the machine to accommodate the different part. Thus, a different machine station may typically be employed to insert each different sized or shaped component. This, of course, greatly increases the capital equipment cost of the product insertion line, and increases the physical space needed to house and support the assembly line. For components which have nonstandard shapes and sizes and/or for which small quantities are used in the circuit, hand labor is typically employed to finish the insertion process for each board, thus further reducing the speed and efficiency by which the boards may be assembled.
The typical prior robotic equipment employs a robot arm which is adapted to be moved through a predetermined sequence of motions. An end effector is connected to the robotic arm and comprises a gripper unit which is adapted to grip each component when the robot arm moves to the component supply location, hold the component while the robot arm traverses from the supply location to the circuit board, and then to release the component when its leads have been inserted through the formed holes in the circuit board. Typically, once all the components have been inserted in the board, either by machine or by hand, the board is moved to a soldering station where the components are soldered to the board.
The prior art robotic equipment known to applicant is unable to handle components of significantly varying sizes and shapes. Thus, a different end effector may typically be required for each different type of component. Moreover, such equipment may typically have problems handling components of the same type, due to variations in the component body from the nominal size and relative to the leads. Since many components are formed from a molded or dipped material, substantial size and shape variations may be encountered, as well as variations of body to lead relationships. Thus, when substantial variations from nominal dimensions are encountered, automatic insertion may not be accomplished and rejection of the component may occur, even though the component is electrically acceptable. Such rejection of electrically acceptable components increases the cost of assembling the board.